Morrisons black flower buckets are available again. They stopped for ages in my local store with the pandemic. They must have a glut, I got 22 for a quid.
Sales of flowers dropped off as folk will not/can not visit, one supposes. if you ask, you can get ex-mayonaise buckets(5ltr?) as well, much sturdier, good for transporting as they have a neat but strong handle, and possibly lids. I paid £1 for 5.